Medical implants such as stents or stent grafts can be used to open blood vessels to mitigate the effects of plaque buildup, as a scaffold to keep embolic material within an aneurysm, as a flow diverter to limit blood flow to certain regions, or for other reasons.
Some implant delivery systems have an outer tubular sheath that contains an elongated “pusher” member on which the implant is disposed. When the distal end of the outer tubular sheath reaches its desired target site, the pusher member can be distally advanced to “push” the implant out of the sheath. In many of these types of delivery systems, the implant is disposed over a portion of the pusher and the pusher further comprises a distal end portion located at or near the distal end of the catheter sheath.
In that regard, as the pusher is distally advance to deploy the implant, the pusher's distal end is advanced well beyond the distal end of the sheath. Depending on the shape and size of the vessel distal of the target site, such distal movement may cause the pusher to contact portions of the vessel beyond the deployed implant. Such contact may result in complications and therefore can be undesirable.